Serum Transferrin Concentrations Research Articles

Microheterogeneity of acute phase proteins in patients with ulcerative colitis.

To estimate the serum alpha1-antichymotrypsin (ACT), alpha1-acid glycoprotein (AGP) and transferrin (Tf) concentrations and to evaluate the microheterogeneity of these acute phase proteins in patients with ulcerative colitis. Twenty-seven patients with ulcerative colitis (UC) and 17 healthy control subjects were studied. The patients were categorised as severe (n = 9), moderate (n = 10) and mild groups (n = 8) using Truelove and Witts' classification of ulcerative colitis. Microheterogeneity of ACT, AGP and Tf was analysed by crossed immunoaffinity electrophoresis (CIAE) with concanavalin A. In all serum samples standard electrophoresis of serum proteins was performed, iron (Fe) concentration, total iron binding capacity (TIBC) and C-reactive protein (CRP) were also measured. Our patients suffering from ulcerative colitis had significantly higher serum ACT and AGP concentrations and lower serum transferrin concentration in comparison to healthy subjects. Changes in concentrations of acute phase proteins were dependent on the activity of the inflammatory process. The glycosylation patterns of transferrin were related to the inflammation status. We also observed the correlation between ACT and AGP concentrations, patterns of transferrin glycosylation and changes in standard protein electrophoresis or blood cell count. The glycosylation patterns of transferrin obtained from patients suffering from ulcerative colitis are highly branched and sialylated compared with those obtained from healthy subjects. In contrast, the glycosylation patterns of transferrin do not differ according to the activity index of ulcerative colitis. The microheterogeneity patterns of AGP and ACT are similar in ulcerative colitis patients and healthy subjects.

Iron Deficiency in Goitrous Schoolchildren of Semirom, Iran

Background: Iodine deficiency produces the spectrum of iodine deficiency disorders (IDDs): endemic goiter, hypothyroidism, cretinism, and congenital anomalies. Other factors, including goitrogens and micronutrient deficiencies, may influence the prevalence and severity of IDDs and response to iodine supplementation. This cross-sectional, descriptive study was performed in 2003 on elementary school children of Semirom, a mountainous region of Iran, where goiter was hyper-endemic in 1994, but the goiter prevalence had not decreased as expected many years after salt iodization and iodine injection. Some possible risk factors associated with goiter in that area were evaluated, and the results of iron study are presented here. Methods: 1,869 cases were selected by a multistage cluster sampling procedure. Grade 2 goitrous children were compared with equal number of nongoitrous children for serum iron, ferritin, transferrin, thyroxin, TSH and urine iodine concentrations (UIC). Results: 210 children (105 goiter grade 0 and 105 goiter grade 2) entered this sub-study. Of 210 participants, 70 children had low transferrin saturation, 13 had low serum ferritin and 9 children had both problems. There was no significant difference in goiter rate between children with low iron indices and others.There was no significant correlation between serum iron, ferritin or transferrin saturation with other variables including T4, UIC and goiter stage. Conclusion: The present study reveals that in the area studied, iron deficiency cannot explain the high prevalence of goiter, so other responsible factors should be investigated.

Iron Status and Risk of Cancers in the SU.VI.MAX Cohort

The aim of the present study was to evaluate the relation between iron status and cancer in a population of middle-aged adults living in France where iron supplementation and iron-fortified foods are rarely used. The SU.VI.MAX study is a randomized, double-blind, placebo-controlled primary prevention trial evaluating the effect of antioxidant supplementation on chronic diseases in women aged 35-60 and men aged 45-60 y. At baseline, concentrations of hemoglobin, serum transferrin and serum ferritin were measured in 10,197 subjects. Data on dietary intake were estimated from six 24-h dietary records completed during the first 2 study years and available for 5287 subjects. All cancer cases that occurred during the 7.5-y follow-up were validated. In men, baseline serum transferrin and serum ferritin concentrations did not differ between subjects with cancers (n = 467) and those without. In women, serum ferritin was higher (P < 0.0001) and serum transferrin tended to be lower (P < 0.08) in cancer cases. Iron status was not related to cancer risk in men, but women with serum ferritin concentrations > 160 microg/L had an increased risk of cancer (odds ratio = 1.88, 95% CI: 1.05,3.35). No relation was found between dietary iron intake and risk of all cancer sites combined for either men or women. Our results suggest that iron status is not a predictor of cancer risk in men, whereas a serum ferritin concentration > 160 microg/L may be associated with an increase in cancer risk in women.

Restless legs syndrome

To assess the prevalence and severity of restless legs syndrome (RLS) in the general community and to investigate its potential relationship with iron metabolism and other potential risk factors. This was a cross-sectional study of a sex- and age-stratified random sample of the general population (50 to 89 years; n = 701). The diagnosis of RLS was established by face-to-face interviews; severity was graded on the RLS severity scale. Each subject underwent a thorough clinical examination and extensive laboratory testing. The prevalence of RLS was 10.6% (14.2% in women, 6.6% in men); 33.8% of all patients with RLS had mild, 44.6% had moderate, and 21.6% had severe disease expression. None had been previously diagnosed or was on dopaminergic therapy. Free serum iron, transferrin, and ferritin concentrations were similar in subjects with and without RLS. However, soluble transferrin receptor (sTR) concentrations were different in subjects with and without RLS (1.48 vs 1.34 mg/L; p < 0.001). Female sex and high sTR independently predicted the risk of RLS. This large survey confirms the high prevalence, female preponderance, and underrecognition of restless legs syndrome in the general community. Although two-thirds of patients had moderate to severe disease, none was on current dopaminergic therapy.

The effect of diets high in protein or carbohydrate on inflammatory markers in overweight subjects

Increased levels of inflammatory markers have been associated with weight gain and cardiovascular disease. The aim of the present study was to investigate the effect of diets high in either carbohydrate or protein on the inflammatory markers C-reactive protein (CRP), haptoglobin and transferrin in plasma after weight loss. Fifty overweight subjects [age: 18-56 years, body mass index (BMI): 27-34] were randomly assigned to an ad libitum, fat-reduced diet (30% of energy, E%), either high in protein and low in carbohydrate (25 E and 45 E% respectively) or high in carbohydrate and low in protein (58 E and 12 E% respectively), during 6 months of strictly controlled dietary intervention with dietary counselling. An average reduction of 25% in CRP and an average increase of 20% in haptoglobin and transferrin were seen in both groups, however, these changes were not significant. In cross-sectional analyses after the intervention CRP was associated with fat mass (r = 0.323, p = 0.03), and the changes in CRP were associated with various indices of body fatness (Deltabody weight r = 0.346, p = 0.02). Changes in body fatness were positively associated with Deltatransferrin (r = 0.344, p = 0.02) and nearly significantly associated with Deltahaptoglobin (r = 0.271, p = 0.07) after 6 months. Multiple regression analysis showed no associations between dietary protein and carbohydrate content and serum CRP, haptoglobin or transferrin concentrations, and this remained unaltered after adjustment for weight change. Dietary carbohydrate/protein ratio has no effect on inflammatory markers, but the study confirmed that body fatness is positively associated with levels of serum CRP.

Changes in Serum Insulin‐Like Growth Factors, Not Leptin, Are Associated With Postnatal Weight Gain in Preterm Neonates

Serum concentrations of conventional nutrition-related proteins, such as albumin, prealbumin, transferrin, and retinol-binding protein, are usually inconsistent with changes in anthropometric measurements in the postnatal period. The aim of this study was to evaluate how reliable growth hormone (GH), insulin-like growth factors (IGFs), IGF-binding proteins (IGFBPs), and leptin, the proteins known to be involved in the regulation of growth, are in reflecting postnatal growth and nutritional status in preterm neonates. Blood samples and anthropometric measurements were collected from 55 preterm neonates (chronological age 30.4 +/- 2.8 weeks) for 4 continuous weeks (weeks 0 to 3). After adjusting for chronological age, body weights and serum IGF-II concentrations were significantly greater and serum transferrin concentrations were significantly lower in weeks 2 and 3 than in week 0 (repeated-measures analysis of variance (ANOVA) and Bonferroni test, p < .05). Forward stepwise multivariate regression analysis showed that change in total IGF-I (week 0 to week 3) was a positive predictor, and changes in insulin and prealbumin were negative predictors of postnatal weight gain. In addition, daily fat intake was a positive predictor of postnatal length increases, and changes in prealbumin, insulin, and GH were negative predictors of postnatal changes in the ponderal index (weight x length(-3)). Changes in GH and IGFBP-2 were negative predictors of changes in head circumference and triceps skinfold thickness, respectively. Serial measurements of serum IGF-I and IGF-II may be useful adjuncts to anthropometric measurements for monitoring postnatal growth and nutritional status in preterm neonates.

Aniline: early indicators of toxicity in male rats and their relevance to spleen carcinogenicity.

Early indicators of aniline hydrochloride (AH) toxicity were investigated in male Fisher 344 rats for 1 or 4 weeks at dietary dose levels of 10, 30 or 100 mg/kg body weight (bw)/day (actual intake at least 6, 17 and 57 mg/kg). The doses were based on earlier studies that had shown spleen toxicity and carcinogenicity in male rats at 100 mg/kg/day but not at 10 mg/kg/day. In the present study a dose-related formation of haemoglobin adducts and Heinz bodies was found from 10 and 30 mg/kg bw/ day, respectively, onwards. Signs of anaemia (decreased red blood cell counts and increased reticulocytes) were recorded from 30 mg/kg onwards. At 100 mg/kg, an overt haemolytic anaemia was associated with increases in serum transferrin concentration and total iron binding capacity in the blood reflecting major perturbations in iron metabolism. At this dose there was an increase in peripheral neutrophil leucocytosis in the blood, indicating an inflammatory process in the spleen. Histopathologic evaluation showed a focal perisplenitis and haemosiderin deposition in sinusoidal Kupffer cells of the liver at 100 mg/kg. These results corroborate the contention that carcinogenic doses of aniline cause early effects on haematological parameters, inflammatory reaction in the spleen and perturbations in iron metabolism as a result of haemolytic anaemia. Accordingly, the carcinogenicity of aniline may be linked to definable threshold-related processes.

Transferrin Microheterogeneity in Fetal Blood

Objectives: To investigate the distribution of microheterogeneous subfractions of transferrin in fetal blood and the influence of highly sialylated transferrins on fetal growth. Study Method: Serum transferrin concentrations were determined by a standard turbidimetric assay. Microheterogeneous transferrin subfractions were assessed by crossed immunoisoelectric focusing. Results: In normal term infants, total serum transferrin concentrations and percent distribution of highly sialylated transferrins (≧5-sialo-transferrins) were markedly lower; the percent distributions of hyposialylated transferrins (0- and 1-sialo-transferrins) were apparently higher than those in non-pregnant and pregnant women. There was no significant positive correlation between the serum concentrations of total transferrin or highly sialylated transferrins in infants’ blood and birth weights (r = 0.187, p = 0.582; r = 0.374, p = 0.257, respectively). Conclusion: The transferrin microheterogeneity pattern shifted towards reduced glycosylation and sialylation in addition to a decrease in total transferrin concentration in fetal blood compared to that of non-pregnant and pregnant women. The concentrations of serum total transferrin and the highly sialylated transferrins in fetal blood, if higher than a certain level, did not seem to have any influence on normal fetal growth.

Transferrin microheterogeneity in pregnancies with preeclampsia

Background: It has been reported that concentrations of serum transferrin (Tf) and its highly sialylated subfraction increase in normal pregnancy. This study investigated changes in the concentrations of serum transferrin and its subfractions in preeclampsia. Methods: The serum concentration of transferrin was determined by a standard turbidimetric assay and microheterogeneous transferrin subgroups (low sialylated, 4-sialo and highly sialylated transferrins) were assessed by crossed immuno-isoelectric focusing. Results: Compared to normal pregnancy, the concentrations of total, 4-sialo and highly sialylated transferrins decreased by 27%, 16% and 38%, respectively, in severe preeclampsia, while these values did not significantly decrease in mild preeclampsia. The concentration of low sialylated transferrin involving 2-sialo- and 3-sialo-transferrins significantly decreased both in mild and severe preeclampsia, the value in severe preeclampsia was even significantly lower than that in nonpregnant women. The serum concentrations of total and highly sialylated transferrins in preeclampsia were correlated positively with infant birth weights ( r=0.587 and r=0.645, respectively). Conclusions: The serum concentrations of total and highly sialylated transferrins in severe preeclampsia decrease significantly. This might have a negative impact on intrauterine growth. Additionally, the serum low sialylated transferrin decreases more sensitively in preeclampsia, although the concentration is low even in normal pregnancy.

Anthropometric measures, cytokines and survival in haemodialysis patients.

Lower serum albumin concentration (sAlb) and higher levels of pro-inflammatory cytokines have been reported to predict death in patients treated with haemodialysis (HD). SAlb, along with anthropometric measures, has been used as a surrogate marker for nutritional status in patients with chronic disease. Though adequate nutrition has been considered an important factor for patients treated with HD, it has not been established if any nutritional markers other than lower serum albumin and lower body mass index (BMI) predict death. Furthermore, it has not been shown whether anthropometric measures other than BMI are associated with predictors of mortality. At the outset of the study, patients were assessed using demographic and anthropometric indices including arm fat area (AFA), arm muscle area (AMA), BMI, per cent ideal weight (PIW), pre-dialysis sAlb, and circulating levels of tumour necrosis factor-alpha (TNF-alpha), IL-1 and IL-6. A severity index, previously demonstrated to be a mortality marker, was used to grade medical co-morbidity. Two-hundred and forty patients entered the study. The mean age was 55.1+/-14.3 years, mean sAlb 3.76+/-0.60 mg/dl, mean AFA 1742+/-1225 mm(2), mean AMA 5464+/-1817 mm(2), mean PIW 101.0+/-21.3% and mean BMI 24.9+/-5.6 kg/m(2). PIW, BMI, AFA and AMA were, as expected, all highly correlated with one another. SAlb correlated with serum transferrin; however, neither sAlb nor serum transferrin concentration correlated with circulating cytokine levels. Circulating cytokines and sAlb did not correlate with PIW, BMI, AFA or AMA. In Cox regression analyses using multiple control variables, IL-6 predicted survival, while the anthropometric measures did not. Pro-inflammatory cytokines and sAlb are robust predictors of death in patients treated with HD. PIW and BMI correlate well with other anthropometric measures in patients treated with HD, but these measures do not correlate with markers of inflammation. Anthropometric measures are poor predictors of survival compared with measures linked to the acute-phase response.

Iron metabolism and erythropoiesis after surgery.

This was a prospective study comparing the effect of major and minor surgery on haematological variables concerning erythropoiesis, iron metabolism and acute-phase response proteins. Thirty-one otherwise healthy patients, 15 having major orthopaedic surgery and 16 undergoing minor surgery, were studied. Blood samples were taken before surgery and 1, 4, 10 and 28 days after operation. Haemoglobin concentration was decreased for up to 4 weeks after surgery. Serum erythropoietin concentration and reticulocyte count were raised after major surgery only. Serum iron concentration dropped the day after major (to 23 per cent of its preoperative level) and minor (to 46 per cent of its preoperative level) surgery and remained lower for up to 28 days after major surgery. Serum transferrin concentration and transferrin saturation decreased after both types of surgery while ferritin concentration increased. Serum transferrin receptor concentration increased only 4 weeks after major surgery (P < 0.01). The interleukin 6 peak (day 1) was greater after major than minor surgery, as was the C-reactive protein peak (day 4). Both major and minor surgery induce a state of hypoferraemia in the presence of adequate iron stores. The degree of this transient form of 'anaemia of chronic disease' is related to the extent of surgery. Iron supplementation in the first weeks after surgery (if iron stores were normal before operation) is ineffective.

Total iron-binding capacity calculated from serum transferrin concentration or serum iron concentration and unsaturated iron-binding capacity.

Total iron-binding capacity (TIBC) indicates the maximum amount of iron needed to saturate plasma or serum transferrin (TRF), which is the primary iron-transport protein (1). Theoretically, 1 mol of TRF [average molecular mass, 79 570 Da (2)] can bind 2 mol of iron (55.8 Da) at two high-affinity binding sites for ferric iron (3). Therefore, TIBC correlates well with TRF concentration, and the theoretical ratio of TIBC (in μmol/L) to TRF (in g/L) is 25.1: TIBC (μmol/L) = 25.1 × TRF (g/L) (4)(5). Measurements of TIBC, serum iron, and the percentage of iron saturation of TRF are useful for the clinical diagnosis of iron-deficiency anemia and chronic inflammatory disorders (6)(7) and as screening tests for other clinical conditions (8). TIBC is routinely determined (9)(10)(11)(12) by saturation of TRF with an excess predetermined amount of iron, removal of the unbound iron, and measurement of the iron that is dissociated from TRF. For removal of the unbound iron, magnesium carbonate (9), ion-exchange resin (10), alumina columns (11), or magnetic particles(12) are used. Most direct TIBC measurement methods require manual procedures that involve centrifugation or pretreatment of serum samples. As an alternative to direct measurement methods, TIBC values are also calculated from the sum of serum iron and unsaturated iron-binding capacity (UIBC), both of which are determined by colorimetric methods (calculation method). We developed a direct and fully automated TIBC (DTIBC) assay for use with an automated multipurpose analyzer (13)(14). A fully automated TIBC measurement method is also commercially available (15). In our previous study (14), TIBC values obtained by DTIBC assay correlated strongly with serum TRF concentrations ( r = 0.984; n = 59), and the slope of the regression line was consistent with the theoretical TIBC/TRF ratio. We …

The assay of ascorbic acid in serum is not affected by physiological concentrations of transferrin and hemoglobin.

Transferrin and hemoglobin have been reported to oxidize L-ascorbic acid (AA) in vitro. The aim of this study was to determine whether or not physiological concentrations of serum transferrin (reference range 22-45 micromol/L) and hemoglobin (reference range 0-3.0 micromol/L) interfer with the measurement of AA in the serum. Transferrin (33 to 41 micromol/L) and hemoglobin (1.9 micromol/L) added to freshly pooled serum significantly decreased measured AA in the serum (p < 0.05). However, we found that the magnitude of the decrease in AA due to transferrin at concentrations within the reference range or up to 80 micromol/L was inconsequential, and had no clinical importance in diagnosing a low AA concentration. Hemoglobin at concentrations within the reference range had little affect on the serum AA measurement. However, when serum specimens were stored at 4 degrees C for more than 1.5 h, the magnitude of the decrease in AA due to hemoglobin at physiological concentrations may cause a misleading clinical diagnostic evaluation of low AA concentration.

Characteristic transfer of colostrum-derived biologically active substances into cerebrospinal fluid via blood in natural suckling neonatal pigs.

The characteristic transfer of colostral components into cerebrospinal fluid (CSF) via serum after natural suckling has been studied by sodium dodecyl sulphate (SDS) electrophoresis, two-dimensional electrophoresis, immunoblot and enzyme linked immunosorbent assay methods in non-suckling pigs. Total protein concentrations in the serum increased immediately after first suckling, reached a peak value at 12 h, corresponding to a 2.3-fold compared with pre-suckling level. The protein concentration in CSF also increased and reached peak value at 6 h corresponding to 1.6-fold compared with presuckling level. IgG in serum not detected before suckling, increased steeply after suckling, IgG, IgM and IgA transported into the serum were observed in completely intact form by immunoblot method. The IgG transported into serum was quickly transferred into CSF after natural suckling in contrast to the case of bovine IgG. Serum concentration of transferrin was maintained at high level before suckling and was not changed by suckling. Transferrin also detected in CSF was not changed by suckling. Bovine lactoferrin (Lf) administered into the intestinal lumen was transported into serum (0.01%) and also detected in CSF after 6 h as undegraded form (3.1%). Thus, homologous IgG and bovine Lf are transported into CSF, suggesting that the transport of macromolecules into CSF is selective in neonatal pigs.

Modification of Fully Automated Total Iron-binding Capacity (TIBC) Assay in Serum and Comparison with Dimension TIBC Method

We previously reported the development of a fully automated assay for total iron-binding capacity (TIBC) in serum, using a multipurpose automated analyzer. However, this method requires four different reagents and is thus useful only with a limited number of available analyzers. We simplified our original assay and compared the analytical performance of the modified method with that of a commercial, fully automated TIBC assay (Dimension TIBC assay). We simplified our original method to require only three reagents. Calibration was also altered and was performed with human transferrin standard solutions. An advantage of this method is that it does not require separation of excess unbound iron after the first step of transferrin saturation. Unbound iron is eliminated by formation of a complex with the chromogenic reagent ferrozine in the second step. Iron dissociated from transferrin by acidic pH reacts with ferrozine to form a colored complex in the final step, and the increase in absorbance at 570/660 nm is directly proportional to the TIBC measured. TIBC values were determined for 49 healthy individuals and 148 patients with this modified TIBC assay and with a commercial, fully automated TIBC method (Dimension clinical chemistry system), and calculation of TIBC based on the sum of the serum iron and unsaturated iron-binding capacity was performed for 97 patients. The within-run CVs for the modified TIBC assay and the Dimension TIBC assay were <4.8% and <2.4%, and the between-run CVs were 1.2% and 1.7%, respectively. The dilution curves were linear for TIBC values up to at least 180 micromol/L with both methods. TIBC values obtained by our method were linearly correlated with serum transferrin concentrations (r = 0.984; S(y/x) = 3.18 micromol/L; P <0.001). The correlation between the values obtained with the present method (y) and those obtained with the Dimension TIBC method (x) was y = 1.04x + 1.19 micromol/L (r = 0.985; S(y/x) = 2.47 micromol/L), and with the calculation method (x) was y = 1.18x + 2.62 micromol/L (r = 0.976; S(y/x) = 3.27 micromol/L). Our modified, fully automated TIBC assay performed similarly to the Dimension TIBC assay and is adaptable for use with many multipurpose automated analyzers.

Pathogenesis and treatment of anaemia of chronic disease

Anaemia of chronic disease (ACD), the most frequent anaemia among hospitalized patients, develops under chronic inflammatory disorders such as chronic infections, cancer or autoimmune diseases. A number of different pathways contribute to ACD, such as diversion of iron traffic, a diminished erythropoiesis, a blunted response to erythropoietin, erythrophagocytosis and bone marrow invasion by tumour cells and pathogens. Nevertheless, ACD is a reflection of an activated immune system and possibly results from an innovative defence strategy of the body in order to withdraw the essential growth factor iron from invading pathogens and to increase the efficacy of cell-mediated immunity.Diagnosis of ACD can be assessed by examination of chances in serum iron parameters with low to normal serum iron, transferrin saturation and transferrin concentrations on the one hand and normal to increased ferritin, zinc protoporphyrin IX and cytokine levels on the other side. Therapy of ACD includes the cure of the underlying the disease. Apart from this transfusions for rapid correction of haemoglobin levels, and human recombinant erythropoietin for prolonged therapy are used. However, response rates to recombinant erythropoietin are sometimes low. Iron alone should be strictly avoided due to its growth-promoting effect towards micro-organisms and tumour cells and because of it capacity to inhibit T-cell-mediated immune effector pathways.We urgently need prospective clinical trials to gain knowledge about the effects of anaemia correction and/or the use of erythropoietin towards the course of the underlying disease, to find out if a combination therapy with erythropoeitin and iron may be beneficial in ACD and to define therapeutic end-points.

CHANGES IN NUTRITION STATUS OF EXPLORERS ON AN UNSUPPORTED SKI TREK ACROSS THE ARCTIC OCEAN

For planning unsupported, long-distance treks, energy content and density of food carried are given primary consideration over micronutrient content due to space/weight considerations. B-vitamins play a critical role in the oxidation and conversion of food to energy, and cofactor requirements increase in proportion to energy expenditure. Additionally, Folate and Iron are key micronutrients necessary to maintain red blood cell production necessary for oxygen transport in support of energy production. The need for micronutrient supplementation during unsupported long-distance trekking is not well defined. PURPOSE: To determine whether micronutrient status changes occur during long-distance, unsupported trekking, which might impact physical performance capacity. METHODS: We obtained blood samples from two Arctic trekkers three weeks prior to beginning their trek and 3 days after completing a 109 day trek. Measures assessed micronutrient status as well as general health indicators. Dietary intake was assessed from self-reported journals. RESULTS: Several food shortages developed during the trek. Bread and cheese were gone on day fourteen, and chocolate on day 100, resulting in intake of iron, folate and B12 below accepted levels. Sausage was depleted on day 45 further decreasing B12 intake. Supplementation with a multi-vitamin tablet was initiated on day 50. The supplement did not contain iron, minerals or B12. Iron intake averaged 8.2 mg/day during the trek and intake was fairly constant from day 14 through 100. Both individuals exhibited a decrease in serum iron and transferrin concentrations to below reference values and ferritin levels were significantly increased at the end of the trek. While these values argue against an iron depleted or deficient state, both individuals had biochemical evidence of anemia (Hb < 13 g/dL) upon completion of the trek. Vitamin B12, folate and measures of vitamin B2 (riboflavin) activity were decreased in post-trek samples. CONCLUSION: Anemia developed due to reduced intake of folate, iron and B12 and decreased oxygen transport capacity. Additionally, the decreases in B-vitamin cofactors, necessary for metabolic flux, may have impacted energy generation capacity. Given the importance of B-vitamins and iron to energy metabolism and oxygen transport, long-distance trekkers should assure sustained intake of iron and B vitamins for the expected trek duration to account for the increased requirements accompanying long term endurance exercise.

Serum Insulin-Like Growth Factor 1 Level and Nutritional Assessment in Nondialytic Patients with Chronic Renal Failure

Aim: In order to understand the nutritional status of nondialytic patients with chronic renal failure (CRF), nutritional assessment was made in 20 nondialytic patients (15 males and 5 females; mean age 43.7 ± 15.1 years). Methods: Twenty CRF inpatients were selected for nutritional assessment, and 20 normal subjects served as controls. The serum insulin-like growth factor 1 (IGF-1) concentration was measured by ELISA. Serum albumin, prealbumin, and transferrin levels were also determined. Results: The mean IGF-I and transferrin levels in the CRF patients were significantly lower than those in normal subjects (IGF-1: 176.2 ± 92.5 µg/l vs. 266.7 ± 101.7 µg/l, p < 0.01; transferrin: 2.57 ± 0.58 g/l vs. 3.18 ± 0.27 g/l, p < 0.05). The IGF-1 levels in 7 patients with a serum albumin concentration <40.0 g/l were significantly lower than those in 13 patients with a serum albumin concentration >40.0 g/l (95.6 ± 42.4 µg/l vs. 219.6 ± 82.7 µg/l, p < 0.01). The IGF-1 levels in cases treated with α-ketoacid were higher than in those without α-ketoacid treatment. The IGF-1 levels were positively correlated with creatinine clearance (r = 0.7066, p < 0.01) and serum transferrin concentration (r = 0.5347, p < 0.05). Conclusions: The fact that serum IGF-1 was correlated with serum transferrin and creatinine clearance suggests that IGF-1 may be a good indicator for assessing the nutritional status of CRF patients. The serum IGF-1 level in CRF patients is probably lower than that in normal subjects and could be improved by nutritional therapy.

Prediction of response to iron sucrose in inflammatory bowel disease-associated anemia

OBJECTIVE: Inflammatory bowel disease (IBD)-associated anemia responds to i.v. iron therapy. However, because of concurrent chronic inflammation, some patients do not respond adequately. Erythropoietin therapy has been shown to be effective in the latter cohort. Our goal was to find parameters that can predict the effectiveness of iron sucrose in IBD-associated anemia. METHODS: One hundred three patients with severe IBD-associated anemia (Hb ≤ 10.5 g/dl) were treated prospectively for 4 wk with iron sucrose (total iron dose = 1.2 g) in an open label, multicenter trial. Treatment response was defined as an increase in Hb of ≥2.0 g/dl. A logistic regression analysis was performed with treatment response as the dependent variable and the following independent variables: serum erythropoietin, mean corpuscular Hb, transferrin, ferritin, soluble transferrin receptor (sTfR), C-reactive protein, interleukin 6 (IL-6), and disease activity. RESULTS: Sixty-seven of 103 patients (65%) responded to iron sucrose. From the variables under investigation, erythropoietin, sTfR, transferrin, and IL-6 were significantly associated with treatment response. The R 2 values showed that erythropoietin (8.0%), sTfR (11.4%), and transferrin (10.4%), but not IL-6 (1.3%), contribute a relevant amount of information to the model. An estimated 80% probability of treatment response was found at erythropoietin levels of >166 U/L, sTfR levels of >75 nmol/L, or transferrin levels of >3.83 g/L. CONCLUSIONS: Serum erythropoietin, sTfR, and transferrin concentrations have the potential to predict the response to iron sucrose therapy in IBD-associated anemia. These parameters may help to identify individuals who benefit the most from additional erythropoietin treatment.

Gestational diabetes mellitus in the last trimester - a feature of maternal iron excess?

To determine whether non-anaemic women with gestational diabetes mellitus (GDM) diagnosed in third trimester pregnancy have evidence of increased iron stores compared with matched non-diabetic controls. In a prospective study, women who had antenatal booking before 20 weeks' gestation and without anaemia or diabetes mellitus were recruited at the time of the oral glucose tolerance test (OGTT) at 28-31 weeks' gestation for the study of serum ferritin, iron and transferrin concentrations. The results were blinded to the managing obstetricians. After delivery, the records were reviewed. The cases diagnosed as GDM were compared with a control group (two controls for each index case matched for parity) selected at random from the at-risk but nondiabetic cases. GDM was diagnosed in 97 of the 401 women recruited. Compared with the 194 controls, there was no difference in the weight, body mass index, booking and third trimester haemoglobin, or third trimester red cell indices, but concentrations of serum ferritin, iron, transferrin saturation, and the post-natal haemoglobin were significantly higher. On multiple regression analysis, maternal BMI and the log-transformed ferritin concentration remained significant determinants of the OGTT 2-h glucose value. The results suggest an association between increased iron stores and glucose intolerance at the third trimester in non-anaemic women. The role of iron excess in the pathogenesis of GDM needs to be examined.